NFL Key Number Analysis for Spread Bettors

Most bettors are already familiar with the concept of key numbers but, for any novice bettors, these are the most common margins of victory. Since field goals are worth three points and touchdowns (including the PAT) are worth seven points, most games are decided by some combination of these numbers.

Using our historical database, I found that “3” has been far and away the most significant number for bettors. Since the start of the 2003 season, 15.04% of all regular season and playoff games (522 of 3471) have been decided by exactly three points and this is crucial for spread bettors. We always advocate that bettors have access to multiple sportsbooks and shop for the best line, but that philosophy is exemplified when we’re dealing with a key number.

The table below displays the most common margins of victory since 2003.

All-Time (2003-2015)

Margin

Occurences

Frequency

3

522

15.04%

7

323

9.31%

10

210

6.05%

6

202

5.82%

4

184

5.30%

14

169

4.87%

1

128

3.69%

2

127

3.66%

17

117

3.37%

8

113

3.26%

21

110

3.17%

13

108

3.11%

5

102

2.94%

11

91

2.62%

24

82

2.36%

20

77

2.22%

18

76

2.19%

28

65

1.87%

16

64

1.84%

12

52

1.50%

27

51

1.47%

15

50

1.44%

9

49

1.41%

31

47

1.35%

25

39

1.12%

19

39

1.12%

23

36

1.04%

22

36

1.04%

34

24

0.69%

35

23

0.66%

29

22

0.63%

38

21

0.61%

26

20

0.58%

30

18

0.52%

32

16

0.46%

33

10

0.29%

37

8

0.23%

41

6

0.17%

45

6

0.17%

42

5

0.14%

40

4

0.12%

36

4

0.12%

0

4

0.12%

46

2

0.06%

39

1

0.03%

44

1

0.03%

58

1

0.03%

43

1

0.03%

52

1

0.03%

48

1

0.03%

49

1

0.03%

55

1

0.03%

59

1

0.03%

56

0

0.00%

47

0

0.00%

57

0

0.00%

51

0

0.00%

53

0

0.00%

54

0

0.00%

50

0

0.00%

These key numbers are also important because most sportsbooks will be hesitant to move off numbers like 3 or 7, instead choosing to adjust the juice if they’re receiving one-sided public action. It also raises an intriguing question regarding whether bettors should buy a half-point when the spread is a key number (also known as buying the hook).

All bettors should be cognizant about rule changes and alterations that could cause the value of historical data to be nullified, and there’s one major rule change that was implemented last season. Prior to the start of the 2015-16 NFL season, the competition committee voted to move the extra point from the 2-yard line to the 15-yard line. This caused the success rate on extra points to drop from 99.3% to 94.2%.

Missed extra points can have massive ramifications for spread bettors since it usually pushes the game off a key number. It can also cause teams to “chase” those lost points by attempting a two-point conversion on their next score. Every point matters, even the extra point.

The table below displays the most common margins of victory during the 2015 season.

2015 Season

Margin

Occurences

Frequency

3

43

16.10%

7

29

10.86%

6

25

9.36%

14

16

5.99%

10

14

5.24%

4

12

4.49%

2

10

3.75%

5

10

3.75%

1

9

3.37%

17

9

3.37%

8

9

3.37%

11

7

2.62%

21

7

2.62%

13

6

2.25%

28

6

2.25%

16

6

2.25%

24

5

1.87%

18

4

1.50%

30

4

1.50%

9

3

1.12%

35

3

1.12%

25

3

1.12%

12

3

1.12%

34

3

1.12%

20

3

1.12%

22

2

0.75%

31

2

0.75%

27

2

0.75%

15

2

0.75%

29

2

0.75%

19

2

0.75%

26

1

0.37%

32

1

0.37%

33

1

0.37%

23

1

0.37%

40

1

0.37%

38

1

0.37%

37

0

0.00%

39

0

0.00%

36

0

0.00%

0

0

0.00%

Although “3” was still the most common margin of victory, the number of games decided by seven points decreased while the number of games decided by six points increased. It’s tough to place much significance on just one season’s worth of data, but it’s logical to speculate that the new extra point rule contributed to this change. It will be interesting to monitor whether that trend continues this upcoming season.

It’s worth noting that these figures don’t account for the closing spread, only the margin of victory. That means that in many instances, the value of shopping for the best line doesn’t even come into play. If a team wins by 40-points, does the closing spread really matter?

In order to examine how often this really comes into play, I examined every game with a closing spread of 2.5, 3 or 3.5. As it turns out, 177 of 1070 games (16.54%) with that closing spread range were decided by exactly three points. That was remarkably similar to the number of overall games decided by three points.

Sportsbooks are obviously hesitant to move their lines off key numbers since they will often get hammered with sharp action if they move. Getting the hook is crucial for long-term sports betting success, which is one reason why our line watcher tool is so valuable.

According to Scott Cooley, an Odds Consultant for the market-setting Bookmaker.eu, they will adjust the juice to as high as -135 on key numbers before moving the spread. He also addressed whether it’s worthwhile to buy half-points around key numbers.

“In general, I do not think buying a half point is a smart move,” said Cooley. “The only time I would suggest is on 3 when you’re expecting a low-scoring game.” This theory makes sense because points are at a premium in low-scoring games, so getting the hook becomes increasingly important.

Cooley went on to state that, “key numbers do factor into our oddsmaking because the public tends to react to them in a more knee-jerk fashion.” He elaborated on that point by saying, “It’s just easier on the eyes in a sense. They see a -3 or a +7 and are more apt to quickly wager on those numbers than a -5.5 or +2.”

The uptick in missed extra points was a great running storyline last season, and it will be interesting to see whether that trend continues going forward. It’s also worth noting that just over half of all games (1,754 of 3,471) have been decided by single digits which speaks to the competitive nature of the league.

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David Solar

David Solar has been the Content Manager at Sports Insights for over four years. He specializes in sports betting analytics and has created several popular data-driven betting systems. He can be reached directly at david@sportsinsights.com or on twitter at @TheDavidSolar.